Tubular frame for furniture

ABSTRACT

The invention relates to improvements in the construction of furniture with tubular frames of hollow profiles, and particularly hollow profiles with oblong, for example oval cross section, adapted to support planar elements, such as walls, plates and shelves. The invention has the object of facilitating the storage of the furniture in its dismantled state, its assembly by the user, and its stability. The furniture is assembled by means of plug-in connections without screws, by providing at least two subframes. The longer axis of the oblong profile is located in the plane of the subframe and retaining elements may be provided to increase the stability of the assembly. Provision is made for the arrangement of drawers, shelves and the like.

United States Patent Schnelle Mar. 7, 1972 [54] TUBULAR FRAME FOR FURNITURE [21] Appl.No.: 866,582

[56] References Cited UNITED STATES PATENTS 1,408,553 3/1922 Wedemann ..211/182 UX 1,473,817 11/1923 Gorsline ..312/257 UX Glass ..312/257 SK Schulze.... .....108/l59 X 3,216,377 ll/1965 Gunn ..108/114 X 3,284,152 11/1966 Schorghuber .312/257 X 3,392,689 7/1968 Ferdinand et al... .....108/110 3,224,823 12/1965 Schulze ..312/257 Primary Examiner-Paul R. Gilliam AttorneyRudolph J. Jurick [57] ABSTRACT The invention relates to improvements in the construction of furniture with tubular frames of hollow profiles, and particularly hollow profiles with oblong, for example oval cross section, adapted to support planar elements, such as walls, plates and shelves. The invention has the object of facilitating the storage of the furniture in its dismantled state, its assembly by the user, and its stability. The furniture is assembled by means of plug-in connections without screws, by providing at least two subframes. The longer axis of the oblong profile is located in the plane of the subframe and retaining elements may be provided to increase the stability of the assembly. Provision is made for the arrangement of drawers, shelves and the like.

2 Claims, 17 Drawing Figures PMENTEDHAR 7 1972 SHEET 1 OF 6 PATENTEUMA'R 7 I972 v SHEET 5 OF 6 PATENTEBMAR 7 I972 SHEET 8 [1F 6 TUBULAR FRAME FOR FURNITURE The invention relates, as indicated, to furniture with frames of hollow profiles which support wall portions, plates, shelves and the like. a

In a preferred embodiment, the invention relates to a construction in which the hollow profiles have an oblong cross section, for example an oval cross section.

In the manufacture of furniture, and particularly of office furniture to which the invention preferably relates, there exists a serious problem in the rational manufacture and the dismantlability of the furniture into preferably flat sections in order to simplify storage and to reduce transport space to a minimum. This should, however, be combined with the easy assembly of the furniture, possibly by the purchaser himself. It is also desirable that the furniture should be capable of being dismantled, for example for subsequent moves without the loss of small parts such as screws and the like.

Known furniture frames, for example of stays with oval cross section are adapted to be assembled by plug-in connections, and the legs may be connected by further stays. These constructions use joints or bridge members, arranged for example at the upper end of the legs in the shape of angles with three legs and provided with lugs into which the hollow profiles are inserted. This construction has the disadvantage that the joints are visible and this visibility is further supported by the special configuration of the surface. For this reason, this type of furniture gives the impression of a workshop construction and this is not always desirable.

In these known constructions all comers and possibly also the stays are assembled by means of these joints and, unless the plug-in connection is very tight, there is the risk of the frame slackening, particularly under load. In order to prevent this from happening, the plug-in connections are made with tolerances such that they can be fitted together only by using special tools or means. In this case, subsequent dismantling is no longer possible. The same also applies where adhesives are used in the region of the joint to hold the fitted parts together.

In another known construction, the plug-in pins are slotted and a spreading device, for example a conical screw is inserted through a predrilled hole or a fitted wedge is shifted by means of a screw. Although this construction makes possible the spreading apart of the legs of the slotted pin, the uniform contact pressure over the length of the pin is lost because the ends of the legs are applied under high pressure and this pressure is reduced towards the root of the legs. The resulting noncontinuous contact pressure also leads to a not very durable connection, quite apart from the fact that the screws represent comparatively complicated and easily lost means.

Another disadvantage of this system is obviously that the higher contact pressure affects only two opposite walls of the hollow profile and no corresponding strength may be achieved in the other direction.

It is another object of the invention to provide furniture with frames of hollow profiles, supporting wall members, plates, shelves and the like in which at least the frames are adapted to be interconnected without the aid of screws so as to produce a stable construction which can, nevertheless, be subsequently dismantled without difficulties, and in which a purchaser may carry out the assembly himself without requiring any special training.

It is a further object of the invention to provide furniture with frames of hollow profiles, carrying wall portions, plates, shelves and the like wherein the frames may be connected without the aid of screws, comprising two subframes each having stays forming two legs and a longitudinal cross stay connecting these stays at the top and comprising at least two cross stays between the two subframes, connected detachably by a mechanical plug-in joint. The subframes provide a firm base for the furniture frame, and the firmly connected stays of each subframe are located in a plane so that the furniture may be collapsed to occupy minimum space. The mechanical plug-in joint makes do without parts liable to be lost.

According to a preferred embodiment of the invention, where a hollow profile with oblong cross sections is used, the

stays forming a subframe are so positioned that the longer axis of the stays forming each subframe is located in the plane defined by this subframe. This construction saves space and enhances the attractive appearance of the furniture as well as utilizing the moment of resistance of the oblong profile to its best advantage.

The mechanical plug-in joint comprises preferably slots at the mounting points for the crossmembers on the subframes and ratchet profiles at the ends of the cross members, engaging behind wall sections of the subframes adjacent to the slots and projecting beyond the crossmembers. In a particularly preferred embodiment the ratchet profiles are hook-shaped lugs adapted to engage into the slots and displaceable therein so that they engage behind adjacent wall portions. The slots have a width adjusted to the lugs engaging therein so as to provide a lateral guide therefor.

In another embodiment, the ratchet profiles are lugs with expanded head sections wherein a narrow shaft under the head section has a height substantially equal to the wall thickness of the stays of the subframe and the slots have at one end a wider section slightly larger than the cross section of the head and in the remaining part a width which is only slightly more than the thickness of the shaft.

In this way, a ratchet profile may be arranged in the cross section of the crossmembers and extend beyond the end face thereof. This construction is provided particularly for crossmembers with a round profile. Preferably however, each end of a crossmember is provided with a profile projecting therefrom at a right angle and having two ratchet profiles which are spaced apart and for which two slots are provided. Such a profile may have, for example the shape of a substantially triangular plate. The arrangement of two ratchet profiles side by side assures not only a certain alignment of the crossmember but guarantees the correct angular arrangement which substantially contributes to the firm assembly of the frame.

According to a preferred embodiment, applying particularly to the use of hook-shaped lugs as ratchet profiles, the profile member has, on the side corresponding to the hook-shaped lugs a mounting surface for the outside of the wall sections of the subframes. In this manner, the wall sections of the sub frames may be firmly fixed.

The mounting may be further improved by providing a wedge for the clamping faces on the ratchet profiles.

The preferred embodiment of the invention comprises at least four crossmembers, one each near the lower ends of the legs of subframe to be locked together and one each near the ends of the longitudinal stays of the subframes. This results, on the one hand, in an attractive appearance, and on the other hand, in a very stable construction, particularly where two ratchet profiles are provided on the ends of each crossmember.

Preferably, also the crossmembers are made of hollow profiles with oblong cross sections and the profile members are arranged in the center of a side with larger dimensions wherein the profiles of the crossmembers near the lower ends of the legs are directed downwardly and the profiles of the crossmembers at the ends of the longitudinal stays are directed towards each other. In this way, the profiles extending from the crossmembers are covered.

The stays forming a subframe are mitered at the connected ends. In a preferred embodiment, however, the stays or the subframes are butt-jointed, wherein the longitudinal stays are fitted to the side walls of stays forming the legs and open towards the top and wherein openings are provided for detachably mounting connecting members. In this manner, a furniture frame formed from two subframes may be extended at choice. For example, the connecting members may be longitudinal stays adapted to engage at each end into a top opening of a leg stay of different subframes. According to another particularly preferred embodiment the connecting members are attachment frames, each with a longitudinal stay and a leg stay, wherein the free end of the longitudinal stay is provided with a mounting device adapted to engage into the openings.

Preferably, the mounting device comprises a pin adapted to fit into the opening of the leg stay and having on its upper surface a tongue so mounted on an upper edge of the longitudinal stay that, when the pin is fitted into the set opening, this Iongitudinal stay is directly retained on the leg stay.

An embodiment of the frame as a table comprises preferably slots on the lower narrow sides of the longitudinal stays and adapted to mount retaining stays for bodies and the retaining stays are constructed at one end with ratchet profiles in the same way as the crossmembers. This makes it possible to connect, by means of mechanical plug-in joints, in the case of a table bodies, and in the case of other furniture attachments.

Preferably, the retaining stays arev connected at the bottom by a crossmember; a base plate with upwardly flanged edges which engage into slots of sidewall members is mounted on this crossmember and on the crossmember between the stays of subframes between the stays of subframes between adjacent legs. This mounting of sidewalls on fiangelike sticks produces a stable arrangement and particularly the mounting of sidewalls without the aid of screws.

In another embodiment, shelves are formed between assembled subframes, providing a cupboard or closet, with a plate mounted above the longitudinal stays. The subframes may be, for example higher than they are long. The principle according to the invention permits the making of frames for all types of furniture such as, for example, file cabinets, counters, bookcases and the like.

According another embodiment of the invention, several groups, each consisting of two subframes, form a wardrobe in which at least one group is equipped with shelves and at least another group for clothes hangers and these groups are connected by at least one common cover plate or are covered by interconnected plates.

Obviously, instead of this solution comprising several groups of subframes, one group consisting of two subframes may be provided with attachment frames on one or both sides, forming an even more economical and compact arrangement.

It should be stated in conjunction with the above descrip tion of the fitting of a body without screws or other complicated fixing elements that the inwardly directed longitudinal sides of the stays forming the legs and/or retaining stays are provided with perforated rails located in a plane perpendicular to the plane defined by a subframe and reversely bent at least partially at the end adjacent to the stay, enabling a wall portion to be fitted by means of a slot in its end face. In this manner sidewalls may be simply pushed in.

A further preferred embodiment of the invention comprises a perforated rail mounted on the rear subframe of furniture and having a reversely bent portion on a web located in the center zone, wherein the perforated rail extends outwardly over the stays of the subframe and has an obliquely bent edge strip for fitting rear wall members with corresponding oblique slots. In this manner a continuous rear wall may be fitted. Obviously, the depth of insertion of the wall portions may be determined by a base plate which may be arranged on the perforated rails or, as described above with upwardly flanged edges engaging with the wall portions. Possibly special abutments may be mounted on the lower ends of the perforated rails.

In yet another preferred embodiment of the invention, the stays of the subframes, and particularly the upper wall sections, are provided with recesses adapted to receive profiles mounted on a top cover plate, for example a table top for universal use or for universal use or for mounting in selective positions.

The invention will be further described by way of example with reference to the accompanying drawings and in the appended claims.

In the drawings:

FIG. 1 is a view in perspective of a frame, consisting of two subframes and four crossmembers;

FIG. 2 is a front elevation of the frame of FIG. I;

FIG. 3 is a corresponding bottom plan view;

FIG. 4 shows on an enlarged scale a partial view, explanatory of a preferred embodiment for a mechanical plug-in joint between a crossmember and a subframe;

FIG. 5 is an end view of FIG. 4;

FIG. 6 is a cross section along the line VI-VI in FIG. 5;

FIG. 7 is a partial view of a longitudinal stay with oblong slots;

FIG. 8 is a front elevational view of a writing desk according to the invention;

FIG. 9 is a perspective view of the frame for the desk of FIG. 8, showing the arrangement of a body;

FIG. 10 shows another type of furniture in the form of a trolley cabinet;

FIG. 11 is a partial view of a larger arrangement for a wardrobe;

' FIG. 12 is a perspective view of another frame construction, for example for a wardrobe, a cabinet or closet;

FIG. 13 shows, on an enlarged scale, a connecting joint in the arrangement of FIG. 12;

FIG. 14 is a partial view, showing a preferred mounting of side wall portions, one leg stay of a subframe being shown in cross section;

FIG. 15 is a side elevation to FIG. 14;

FIG. 16 is a view corresponding to FIG. 14, showing a leg stay in cross section and means for fixing a rear wall portion without the aid of screws; and

FIG. 17 is a side elevation to FIG. 16.

Identical parts are designated by the same reference numerals in FIGS. 1, 2 and 3. The furniture system will here be explained with reference to the embodiment of a desk frame. The desk frame consists of two subframes 1 and 2, each consisting of stays 3, 4 and 5, 6, respectively, forming the legs and a longitudinal stay 7 and 8 connecting the legs on the top. In the following a preferred embodiment will be explained in which the stays are tubular profiles with oblong cross sections. The stays 3 through 6 forming the legs are connected at the top corners rigidly, for example by welding, as at 9, 10, 11 and 12. Furthermore, the arrangement of the profiles is such that the longer axis of the oblong profile is always located in the plane defined by the associated subframe 1 or 2, as shown more particularly in FIG. 3.

The two subframes I, 2 are connected by crossmembers l3, 14, 15, 16 having the same configuration of the cross section as the subframe stays. Their ends are connected detachabl y to the subframes by mechanical plug-in joints. These joints are indicated, by substantially triangular profiles 17, I8 connected to the crossmember 13. As shown in FIG. 3 these profile members are directed inwardly, i.e., towards the center of the frame in the same manner as those of the crossmember I4. it may also be seen that these profiles are mounted on one side of the associated crossmember having the larger dimension. Corresponding profiles 19, 20 are provided at the ends of crossmembers 15, 16, connecting the legs at the bottom and face downwardly. As shown these crossmembers 15, I6 are positioned so that the longer axis of their cross section is.

horizontal.

A preferred embodiment of a mechanical plug-in joint using profiles of this type will now be explained with reference to FIGS. 4 through 7. The drawing shows by way of example a part of the longitudinal stay 8 and a part of the crossmember 14. In the fixing position, the longitudinal stay has'two slotted recesses 21, 22. The width of these recesses is such that projecting ratchet profiles 23, 24 on the profile member 25 are adapted to be guided laterally in the said slots. In the preferred embodiment shown, the ratchets 23, 24 have the shape of hooklike projections, starting from one edge 26 of the profile member 25, aligned with the end face 27 of the cross member 14 and extending at a rightangle to the longitudinal axis thereof. The hook-shaped lugs 23, 24 have webs 28, 29, extending parallel to the edge 26 and so spaced therefrom that they may be fitted tightly into the slotted recesses 21, 22 of adjacent wall portions 30, 31. The length of the slotted recesses 21, 22 slightly exceeds that of the webs 28, 29.

As shown in FIG. 5, the longer axis of the profile of the crossmember 14 is shorter than the longer axis of the profile of the longitudinal stay 8, the dimensioning being such that the crossmember 14 extends only over the straight portion of a longer sidewall 32 of the longitudinal stay. Where identically dimensioned profiles are used for the crossmembers and subframes, the end face of the crossmembers has a concave shape so that the end sections with the shorter curved sides match the curvature of the longitudinal stay 8 at the edges of the side wall 32. This produces a flush and closed connection.

It may be seen from FIG. 5 that the profile member 25 is arranged along the center line of the crossmember 14. It is fitted with a section 33 into a prepared slot 34 of one broad side of the crossmember and may, where the parts are made of metal, be connected for example by welding.

The correct angular mounting of the edge 26 of the profile member 25, and the arrangement of two ratchet profiles 23, 24 produces a firm mounting and the accurately rightangled positioning of the crossmember 14. Furthermore, the webs 28, 29 of the hook-shaped profiles may have a slightly wedgeshaped configuration such as 35, 36 in FIG. 4 on the underside, to improve the seat.

This type of mounting which also applies to the crossmembers 15, 16 in FIG. 1 shows that an even involuntary use of the cross members 15, 16 as leg supports can only serve to improve but not to slacken the mounting.

The desk shown in FIG. 8 has a front subframe 37, which may correspond to the subframe 2 of FIG. 1. The longitudinal stays, of which one is shown at 38, carry a table top 39 which is also mounted by means of hook profiles, the recesses for which are provided in the vertical sides of the longitudinal stays.

The desk of FIG. 8 has a body 40, retained on one side by the stays 41 of the subframes, forming the legs, and on the other side by two mounting stays 42. The mounting stays 42 have at their top ends mounting means as shown in FIGS. 4 through 6 for the cross member 14. These mounting stays are also mounted in slots on the underside of the longitudinal stay 38 so that also the body may be mounted without the aid of screws.

FIG. 9 shows the frame for the desk of FIG. 8, constructed in the same way as shown in FIG. 1 and using therefor also the same reference numerals as in FIG. 1 with the exception of the front subframe which is referenced 37. The retaining stay 42 cooperates with a corresponding retaining stay 80 on the longitudinal stay 8. A crossmember 81 mounted at the same height as the crossmember connects the retaining stays 42, 80 at the bottom. It should be noted that the retaining stays 42, 80 and the cross stay 81 may also be made in one part because this generally U-shaped frame member is located in one plane in the same way as the subframes hitherto described.

The crossmembers 15, 81 serve to support a base plate 82, the edges 83, 84 of which are angled upwardly at the sides 85 and at the back. Slots of wall portions are fitted over these edges, as described further below with reference to FIGS. 14 through 17.

FIG. 10 shows a comparatively small cupboard 43 with two shelves. The drawing shows the front subframe 44. In this embodiment, the longitudinal stays, of which one is shown at 45, are shorter than the stays forming the length of the cupboard. The upper longitudinal stays are again covered by a plate 46 which may be fixed as described with reference to the table top 39 in FIG. 8.

The lower ends of the legs are provided with casters 47, 48. If suitably dimensioned, this cupboard may be placed as movable attachment table under the desk top 39 instead of the body 40 in FIG. 8.

The principle of the invention, based on subframes and stays adapted to be fitted by a mechanical plug-in joint, may also be used for file cabinets, bar counters, push trollies, bookcases, card index cabinets, cabinets for suspended indices and the like. The universal application of the components of the system makes also possible the economical manufacture, for

example of sound-proofing partitions. This latter application uses one or two subframes in conjunction with base elements. Thus, the invention makes possible the execution of a complete furniture manufacturing program.

FIG. 11 shows a part of a wardrobe or closet. This may consist of two sets of frames, of which the drawing shows the front subframes 49, 51. The subframes forming one group are assembled by crossmembers, as described above. The center group with the subframe 49 may be equipped, for example, with drawers 52, whilst the outer group with the subframes 51 is equipped, for example, with rods for clothes hangers. The longitudinal stays 53 of the front subframe 51 may be provided with curtains, the curtain rails of which may be adapted to be placed into openings provided to this end or the rails may be hidden behind the longitudinal stays 53.

The drawing also shows a longitudinal stay 54. This stay 54 is hooked into the stay of the subframe 49 forming the leg 50, in order to extend the arrangement, as described further below with reference to a special frame shown in FIG. 12. The construction incorporating the fitting of the longitudinal stay 54 provides an additional group. These three groups are covered at the top by a plate 55 to form a unit. Conveniently, the outside may be covered by a curtain extending thereover.

FIG. 12 shows similar to FIG. 11 a subframe 49 with a stay 50 forming a leg. This subframe is associated with a corresponding rear subframe 86 having leg stays 87 and 88. The subframes may be connected to each other by three crossmembers 89, 90, 91. It should be noted that the hollow profiles of the leg stays 87, 88, 50 are continuous towards the top and form an opening at the top whilst the longitudinal stays 92, 93 abut on the sides of the leg stays and are fixed thereto, for example, by welding.

This frame construction is extended towards the right by two attachment frames 94, 95 consisting each of a leg stay 96, 97 and a longitudinal stay 98, 99. The free ends of the said longitudinal stays engage with fixing attachments 100, 101 into the top openings of the leg stays 50, 88. The attachment frames 94, 95 may be connected, for example, by crossmembers 102, 103, as described hereinbefore.

FIG. 13 shows in detail the joint for the attachment frames; the drawing shows a part of the longitudinal stay 93, the leg stay 50 firmly connected therewith, and the longitudinal 'stay 98 of the attachment stay 94. The leg stay has a top opening 104. Into this top opening a pin 105 is fitted, having substantially a cross section corresponding to that of the opening 104. This pin is joined by a rigid plate 106 with the upper narrow side of the longitudinal stay 98 at such spacing that, after the pin 105 has been inserted into the opening 104, this longitudinal stay is retained directly on the leg stay 50. Obviously, the end face of the longitudinal stay may have a concave edge matching the curvature of the leg stay and ensuring a flush connection.

This type of extending a frame according to FIG. 12 may be used for all types of furniture, given the suitable dimensioning of the subframes and of the attachment frames and is particularly suitable for flow tables and continuous records.

FIGS. 14 through 17 show examples for mounting wall portions, such as may be used for a desk as shown in FIGS. 1 or 8. FIGS. 1 and 15 show, by way of example, the front stay 41, 3 forming part of the subframe 37, 2 and FIG. 16 and 17 the corresponding leg stay 56, 51 forming part of the subframe 1 in FIG. 1 and forming a rear leg of the desk. Oweing to the chosen arrangement of the profiles in the subframes, a larger side 57, 58 of the leg stay is available for mounting perforated rails 59, 60. These perforated rails may be fitted by means of lugs 61, 62 tightly into prepared openingsfif the leg stays.

The perforated rail 59 for the front si c has on the mounting portion a weblike reverse bend 63 and on the inside a part 64 with a row of square holes 65, 66. These rows of holes are known in the art for suspending telescopic rails for shelves or the like. At the end remote from the leg stay 41, 3, there is a generally U-shaped bend 67, the section 68 of which, extending parallel to the section 64, is located in a plane which is neared to the section 64 than the plane of the reverse bend 63. Thus, in this construction, for example after assembling the frame, as shown in FIG. 1, a sidewall portion 69, having a slot 70 in its end face can be pushed over from the top so that the slot engages over the flange of the reverse bend 63.

The rear end of the perforated rail 60 equipped with a row of square holes 71, 72 has a weblike reverse bend 73 at the mounted end. This bent portion 73 is aligned with the weblike reverse bend 63 and engages into an end face slot 74 of the fitted side wall portion 69.

In order to improve the stability of the arrangement, the perforated rail 60 has at the end remote from the leg stay 56, S a bend 75 reaching to the sidewall portion 69. Simultaneously, however, the perforated rail 60 also serves to mount a rear wall portion 76. To this end a section 77 is fitted to the perforated rail 60 and extends beyond the leg stay 56, towards the rear or outside beyond the subframe. This section 77 has on obliquely bent edge strip 78 adapted to receive a rear wall portion 76 which is equipped with corresponding oblique slots 79.

As already hereinfore mentioned, the adjustment in height of the wall portions is achieved by means of suitable profiles on the perforated rails 59, 60 or by a base plate such as 82 in FIG. 9.

I claim:

1. A furniture frame made of tubular members having hollow profiles of oblong cross section and adapted to support elements such as wall portions, plates or shelves, said frame comprising a first and a second subframe, each of the subframes comprising two stays forming two legs and a longitudinal stay connected to the upper ends of the two legs, the two legs and the longitudinal stay of each subframe lying in a common plane and being rigidly and permanently connected together, with the longer axes of the oblongs all located in the median plane of the subframe; a first pair of crossmembers detachably connected between corresponding legs of the two subframes by means of a mechanical plug-in connection at points proximate to the free ends of the legs, said crossmembers each having a length less than that of the longitudinal stays of the subframes, and the longer axes of the oblongs coinciding with the corresponding axes of the legs; and a second pair of similar crossmembers detachably connected between the longitudinal stays of the two subframes by means of a mechanical plug-in connection at points proximate to the ends of said stays, the longer axes of the oblongs coinciding with the corresponding axes of the stays; wherein each of the mechanical plug-in connections comprises a pair of axiallyspaced slots formed in the subframe, and a triangular plug-in member secured to the crossmember and having a pair of hook-shaped projections extending beyond the end of the crossmember, said hook-shaped projections being insertable through the said slots and slidable into engagement with the inner wall of the subframe; the triangular plug-in members secured to a particular crossmember lying in a plane containing the short axis of the oblong; the triangular plug-in members secured to the. said first pair of crossmembers being directed toward the free ends of the legs; and the triangular plug-in members secured to the said second pair of crossmembers being directed towards each other.

2. A furniture frame as set forth in claim 1, used as a desk, including means forming axially-spaced slots in the lower narrow wall of each of the longitudinal stays of the said first and second subframes; a third subframe comprising a crossmember rigidly secured to the ends of a pair of retaining stays; triangular plugin members secured to the free ends of the said retaining stays and having hook-shaped projection, said hookshaped projections being inserted into the corresponding slots formed in the said narrow walls of the longitudinal stays; and a base plate mounted on the crossmember of the said third subframe and one of the crossmembers positioned adjacent to the lower ends of corresponding legs of the said first and second subframes.

1i a a 1 

1. A furniture frame made of Tubular members having hollow profiles of oblong cross section and adapted to support elements such as wall portions, plates or shelves, said frame comprising a first and a second subframe, each of the subframes comprising two stays forming two legs and a longitudinal stay connected to the upper ends of the two legs, the two legs and the longitudinal stay of each subframe lying in a common plane and being rigidly and permanently connected together, with the longer axes of the oblongs all located in the median plane of the subframe; a first pair of crossmembers detachably connected between corresponding legs of the two subframes by means of a mechanical plug-in connection at points proximate to the free ends of the legs, said crossmembers each having a length less than that of the longitudinal stays of the subframes, and the longer axes of the oblongs coinciding with the corresponding axes of the legs; and a second pair of similar crossmembers detachably connected between the longitudinal stays of the two subframes by means of a mechanical plug-in connection at points proximate to the ends of said stays, the longer axes of the oblongs coinciding with the corresponding axes of the stays; wherein each of the mechanical plug-in connections comprises a pair of axially-spaced slots formed in the subframe, and a triangular plug-in member secured to the crossmember and having a pair of hook-shaped projections extending beyond the end of the crossmember, said hook-shaped projections being insertable through the said slots and slidable into engagement with the inner wall of the subframe; the triangular plug-in members secured to a particular crossmember lying in a plane containing the short axis of the oblong; the triangular plug-in members secured to the said first pair of crossmembers being directed toward the free ends of the legs; and the triangular plug-in members secured to the said second pair of crossmembers being directed towards each other.
 2. A furniture frame as set forth in claim 1, used as a desk, including means forming axially-spaced slots in the lower narrow wall of each of the longitudinal stays of the said first and second subframes; a third subframe comprising a crossmember rigidly secured to the ends of a pair of retaining stays; triangular plug-in members secured to the free ends of the said retaining stays and having hook-shaped projection, said hook-shaped projections being inserted into the corresponding slots formed in the said narrow walls of the longitudinal stays; and a base plate mounted on the crossmember of the said third subframe and one of the crossmembers positioned adjacent to the lower ends of corresponding legs of the said first and second subframes. 